Sleep appliance



FIG. 1 is a top front perspective view of a sleep appliance.

FIG. 2 is a top view thereof.

FIG. 3 is a bottom view thereof.

FIG. 4 is a front view thereof.

FIG. 5 is a rear view thereof.

FIG. 6 is a left side view thereof; and,

FIG. 7 is a right side view thereof.

The broken lines in the figures are included for the purpose of illustrating portions of the sleep appliance that form no part of the claimed design. 

CLAIM The ornamental design for a sleep appliance, as shown and described. 